Policy network analysis is a field of research in political science focusing on the links and interdependence between government's sections and other societal actors, aiming to understand the policy-making process and public policy outcomes. Policy network analysis is a field of research in political science focusing on the links and interdependence between government's sections and other societal actors, aiming to understand the policy-making process and public policy outcomes. Although the number of definitions is almost as large as the number of approaches of analysis, Rhodes:426 aims to offer a minimally exclusive starting point: 'Policy networks are sets of formal institutional and informal linkages between governmental and other actors structured around shared if endlessly negotiated beliefs and interests in public policy making and implementation.' As Thatcher:391 notes, policy network approaches initially aimed to model specific forms of state-interest group relations, without giving exhaustive typologies. The most widely used paradigm of the 1970s and 1980s only analyzed two specific types of policy networks: policy communities and issue networks. Justifications of the usage of these concepts were deduced from empirical case studies. Policy Communities in which you refer to relatively slowly changing networks defining the context of policy-making in specific policy segments. The network links are generally perceived as the relational ties between bureaucrats, politicians and interest groups. The main characteristic of policy communities – compared to issue networks – is that the boundaries of the networks are more stable and more clearly defined. This concept was studied in the context of policy-making in the United Kingdom. In contrast, issue networks – a concept established in literature about United States government - refer to a looser system, where a relatively large number of stakeholders are involved. Non-government actors in these networks usually include not only interest group representatives but also professional or academic experts. An important characteristic of issue network is that membership is constantly changing, interdependence is often asymmetric and – compared to policy communities – it is harder to identify dominant actors. New typological approaches appeared in the early 1990s and late 1980s with the aim of grouping policy networks into a system of mutually exclusive and commonly exhaustive categories. One possible logic of typology is based on the degree of integration, membership size and distribution of resources in the network. This categorization – perhaps most importantly represented by R. A. W. Rhodes – allows the combination of policy communities and issue networks with categories like professional network, intragovernmental network and producer network. Other approaches identify categories based on distinct patterns of state-interest group relations. Patterns include corporatism and pluralism, iron triangles, subgovernment and clientelism while the differentiation is based on membership, stability and sectorality. As the field of policy network analysis grew since the late 20th century, scholars developed competing descriptive, theoretical and prescriptive accounts. Each type gives different specific content for the term policy network and uses different research methodologies. For several authors, policy networks describe specific forms of government policy-making. The three most important forms are interest intermediation, interorganizational analysis, and governance.